driver core: revert "device" link creation check

Commit 2ee97caf introduced an extra
check on when to create the "device" symlink. Unfortunately, this
breaks input, so let's revert to the old behaviour.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>